Fabien COELHO <coelho(at)cri(dot)ensmp(dot)fr> writes:
> For checking variable definition, I would suggest to extend the variable
> access syntax so that there is no exception to the one thing rule between
> client side and server side evaluation:
> \if :?variable
Don't like that one bit; you're going to run out of namespace there
in no time. And you don't have a very good way to say "if not defined",
either.
regards, tom lane